inners, painted 'em....it cracked

rubbersidedown

TURBO-BUSA-RIDIN'-BASTID
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whadda ya think Rubb did wrong ?

Used a high quality cleaner , hi-Q adhesion promoter, quality hi-build , 2 good coats of color , 3 of clear....

what happened ? It cracked but didn't fall off.

hav a smooth 1.....RSD.
 
What kind of hi-build primer did you use? Maybe you built up too much film thickness? Hard to say without knowin' exactly what all you used and how much of each you applied. The thicker the finish, the easier it cracks. I'm suspectin' that with high build primer on it, you had too much film thickness, therefore it wasn't flexible enough for a flexible part such as an inner. Just a guess though since I can't see it from here.
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I have 37 or 38 painted parts on my Busa, its only 2 of the dash pieces that have givin' me grief....

your thoughts Chris......

I wet sanded them to 400.
Cleaned them.
Adhesion promoter.
Hi build , just enuff to cover the ruff( 5 coats)
Sealer.
2 of the color.
3 coats of clear.
 
Ding ding ding... we have a winner. I believe the culprit is in the photo below. If you used 5 coats of this, I can almost guarantee that's why it shattered like glass.



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Anyway... I'll check this thread again in the mornin'. I've gotta hit the sack so I can get up for work on time.

To explain further, I've never had much luck usin' epoxy on plastic or fiberglass. Pretty much always ended up crackin' on me. I've always used urethane only on flexible stuff and plastic/'glass. The eopxy products are usually 1 coat, or maybe two coat max products. five coats of an epoxy will make one hell of a thick paint film thickness by it's self. Then add sealer, paint, clear... Just too much material stacked on a flexible, expanding/contracting plastic part.

I still haven't got my hands on a set of inners to play with so I can't really give specific prep and coating advice on 'em. Maybe I can find some ***CHEAP*** ones somewhere one day to play with. I could prolly make decent money just paintin' inners and such. Just don't want to experiment on other peoples' poop. Not the way I do bidness...

I bet if this is the case, and you used 5 coats of epoxy, I bet you can totally strip 'em usin' nothin' more than an air hose, blowin' high pressure air into the cracks. Prolly no adhesion at all with that much thickness. I've done it and seen it done on cars when folks went overboard with the epoxy. Comes off of a car in sheets as big as yer hand when you hit a crack with compressed air...

I could be off base here, but goin' by what I've seen in this thread and seein' that pic of the cracks, I'd almost bet cash money I'm right.
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Holy crap Rub....that's insane....never seen peelin that bad....wouldn't even call it crackin or peelin....I'd call it shedding.
Bullet's right on the money bro imho.
Bet ya it looked smooth as glass before it peeled though.
How are the top ones??
 
ooooooooo ouch!  Looks like it lost a fight with a nine iron!  Just stick a band aid on it and youll be straight!
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 ... not really though... but BT sounds like he knows what he is talking about.  ( kinda common sense if ya think about it )

It just goes to show that you CAN have to much of a good thing!  
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Reason for Edit: "I am a dumb YANK!!! thats why!"|1094186018 -->
 
I'm not a painter by any means (that would really mean not at all), but from what I have read on some other inner paint jobs you were missing a flex agent. I could just be missing it somewhere, so forgive my stupidity if that's the case. Again, I am no painter!
 
I'm not a painter by any means (that would really mean not at all), but from what I have read on some other inner paint jobs you were missing a flex agent. I could just be missing it somewhere, so forgive my stupidity if that's the case. Again, I am no painter!
I never use flex additive on anything. As I said, I haven't painted a set of inners to see what it's gonna take to make 'em last, but I've painted plenty of parts that were more flexible than the inners are.

The problem the ol' bastid is havin' here is definitely not caused by not havin' flex additive in the finish. Would have made no difference with 5 coats of epoxy underneath the paint...
 
Hmmm... He must still be drinkin' away the pain of seein' the paint bustin' up on his baby...
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Ding ding ding... we have a winner. I believe the culprit is in the photo below. If you used 5 coats of this, I can almost guarantee that's why it shattered like glass.
no it wasn't that shid BT , I used 5 coats of Hi-Build as suggested by Monsta.
So where's the pic of the hi-build can? Didn't see it in the pics above.
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What kind was it?

I'm still leanin' toward too much paint film thickness. Still don't like the idea of usin' epoxy on plastic either. Let me know what kind of hi-build you used and we'll go from there...
 
Epoxy will not stick to plastic. I use Autocryll when I used to do Inner Fairings. I 4 years I never had a set that cracked or peeled. Unfortunately Autocryll is not sold here in the U.S and it is very hard top find. It is used on your High High High dollar Sportcars that are made from composite materials
 
I'm not a painter by any means (that would really mean not at all), but from what I have read on some other inner paint jobs you were missing a flex agent.  I could just be missing it somewhere, so forgive my stupidity if that's the case.  Again, I am no painter!
I never use flex additive on anything. As I said, I haven't painted a set of inners to see what it's gonna take to make 'em last, but I've painted plenty of parts that were more flexible than the inners are.

The problem the ol' bastid is havin' here is definitely not caused by not havin' flex additive in the finish. Would have made no difference with 5 coats of epoxy underneath the paint...
That's why I'm no painter!
 
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